Coal washer box



B. NORTON COAL WASHER BOX May 22, 1934.

Filed May 11. 1951 I l/YVf/VMR- l3 NOR To/v.

Patented May 22, 1934 TENT OFFICE COAL WASHER BOX Bertram Norton, Claverley, England Application May 11, 1931, Serial No. 536,560

In Great Britain May 14, 1930 6 Claims.

This invention relates to washer boxes for coal and the like of the type in which materials of different density such as coal and shale are separated by being subjected to the pulsating action of water in which they are immersed, the pulsations being produced by the action of compressed -air. In such boxes the coal and shale to be separated are usually admitted to a compartment arranged along one side of the box and having a perforated bottom through which the water rises and falls in pulsations, and this compartment is separated from the other side of the box by a vertical partition extending downwards below the bottom of the compartment but terminating above the bottom of the box so that Water can pass freely under the partition from one side of the box to the other. The side of the box not containing the actual washing compartment has a closed top arranged at about the level of the top of the washing compartment and serving as a mounting for the control or shifting valves through which compressed air is admitted. Thus the compressed air acting in pulsations upon the surface of the water in the one side of the box causes the water in the other side of the box to rise and fall through the perforated bottom of the washing compartment.

The present invention is based upon the observation that, when the operation of the box is stopped, the water level sinks below the level of the water outlet in the washing compartment, thus showing that during operation the water level in the compressed air side of the box is considerably lower than the level in the washing compartment side. The present invention consists in placing the top of the air chamber at a level at least as low, and preferably substantially lower than the water outlet of the box, and above the level of the grid or perforated bottom of the washing compartment. The top of the air chamber is thus placed at a considerably lower level than it has been placed in any box hitherto, so that when the operation of the box is stopped the static or natural water level in the compressed air side of the box is only just below, or may even be above, the top of the box. This arrangement has the great advantage that when the operation is begun again, the volume of air which has to be introduced is considerably smaller than has been the case hitherto, and thus the amount of power required is less.

As explained above, in general the water level in the box falls at the cessation of operation to a level well below the water outlet of the washing compartment, but sometimes water continues to run into the box until the level rises to that of the water outlet and water overflows slightly from the box. In these circumstances when compressed air is admitted to begin washing opera tions again, the water in the air chamber is, of course, depressed with the result that a corresponding volume of water is displaced and caused to overflow from the washing compartment. A further feature of the invention consists in actually placing the top of the air chamber below the level which the water naturally takes up when the operation is stopped and in providing pipes leading upwards from the air chamber to the air control valves. In these circumstances if the water in the whole box rises on the air chamber side, the rise can take place only in the pipes so that when the operation begins again the volume of water which overflows through the water outlet in the washing compartment is very much reduced.

In order that the invention may be clearly understood and readily carried into effect, one form of washer box constructed inaccordance therewith will now be described by way of example with reference to the accompanying draw- 30 ingwhich shows purely diagrammatically an end view of the box partly in cross-section. Referring to the drawing, coal and shale to be washed are admitted to a compartment 1 having a perforated bottom 2 which is mounted along one side of the box 3. A vertical partition 4 extends downwards into the box for some distance below the bottom 2 of the washing compartment 1. Compressed air is admitted to the surface of the water on theside of the partition 4 remote from the washing compartment 1 by means of a series of control valves arranged along the length of the box, of which one is shown at 5. In normal operation the level of the water in the washing compartment side of the box is approximately at the line AA, which also represents the level of the water outlet from the washing compartment 1, while under the influence of the air pressurethe level of the water on the air chamber side of the partition 4 is approximately at the line B-B. When the valve 5 opens so that further compressed air is admitted, the water level in the air chamber side of the box falls to the line C-C and in the 0 washing compartment rises to the line DD. Thus in operation the water level is continually moving between the levels BB and C-C and A-A and D-D respectively. When washing operations are stopped the Water in the whole box a cover for said takes up its static or natural level shown approximately by the line E-E.

The top of the air chamber is shown at 6 and is placed just below the level E-E. Thus, the volume occupied by the compressed air in normal working is only that between the top 6 of the air chamber and the level water in the air chamber, this volume showing a very considerable reduction in comparison with prior washer boxes in which the top of the air chamber has been arranged approximately at or near to' the" top of the washing compartment 1.

The air is admitted from the valve 5 down a pipe '7 to the air chamber. By virtue-ofthis arrangement if, after the cessation of washing operations, water continues to'run into the'box through the water inlet 8,.iuntil the level in the whole of the box reaches the wateroutlet ofthe washing compartment, that is the line A--A, the water on the air chamber side of the box will :only. rise upithe pipe 7-so thatby means of the ,constructionshown only a minimum amount of water is displaced when the airpressureis applied-againthrough the valve 5 and pipe 7.

, I claim:

, 1. .Ina coal washer box of the pistonless type, a

washing chamber. and Ya pistoning chamber adjacent thereto, a conduit. connecting :the bottoms-of said washing chamber and said pistoning chamber a perforated plate in said washing chamber adapted to receive material to be washed, saidwashing chamberv being provided with-a water outlet abovev said perforated plate, pistoning chamber arranged intermediate the-levelof saidwater outlet and of said perforated plate, and-means including --avalvelocated-above thevwateroutlet for con- .ducting compressed pistoning. air .to .and away from said pistoning chamber throughsaid cover.

2. In a coal washer-box of thepisto'nless type, a washing chamber and a.-pistoning chamber adjacent thereto, a conduit connecting the bottoms of said washing chamber and said pistoning chamber, a perforated plate in said washing chamber adapted to receive material to be washed, said washing chamber being provided with a water outlet above said perforated plate, a cover for said pistoning chamber placed in said box at a level substantiallybelow that-of the said water. outlet and above said perforated plate, and means for conducting compressed pistoning air'to and away from said pistoning chamber through said cover.

3."In a coalwasherbox of the pistonless type, the combination of a container for water, a vertical-wall extending downwards into'said container but notreaching the bottom thereof and serving to divide said container into twocompartments, a perforated bottom to one of" said compartments, said compartment being adapted to receive-material to be'washed and being provided with-a water outlet a cover for said second compartment, said cover being placed'at' a; level in the boxsubstantiallYbelow that of the said water outlet from'the .first compartment and above the level of said perforated bottom,

and a pistoning chamber,

above the level of said perforated bottom, and means for conducting compressed air into and away from said second compartment through said cover.

4. In a coal washer box of the pistonless type, the combination of a container for water, a vertical wall extending downwards into said container but not reaching the bottom, thereof, and serving tof-divide said container into two compartments, a perforated bottom to one of said compartments, said compartment being adapted to receive material to be washed and being provided with a water outlet, a cover for said second compartment, said cover being placed at a level in the box substantially below that of the said water outlet from the first compartment and and means, including air control valves arranged above the level of the water outlet, for admitting compressed air to said second compartment, said air-control valves being connected to the interior of said-compartment by means of upwardly extending pipes.

5. In a-coal washer box of the pistonless type, a washing chamber'and a pistoning chamber adjacentthereto, a conduit connecting the bottom of said washing chamber and said pistoning chamber, a perforated plate in said washing chamber c adapted to receive material to be washed-said washing chamber being provided withawater outlet above said perforated plate,

a cover for said pistoning chamber, a conduit for conveyingcompressed pistoning air through said' cover to and away from said pistoning chamber, a valve in said conduit for controlling theflow of said pistoningair to and from said pistoning chamber, said valve being located above the level ofsaid water outlet and said cover being located substantially below said water outlet-but abovev said perforated plate.

6. In a coal washer box, a washing chamber a conduit connecting thebottom .of said washing chamber and said pistoning-chamber'so that said washing chamber and said pistoning chamber can contain acommon body of water, a perforated plate in said washing chamber adapted to receive material tobe washedrsaidwashing chamber, pistoning chamber-and conduit being devoidof means restricting free oscillation of said common body of watersave for said perforated plate a water outlet from said washing chamber arranged above said perforated plate, a cover for said pistoning chamber, a conduit for conveying compressed pistoning. air through said cover to and away from the surface of water in said pistoning chamber, a valve in said conduit for controllingv the now of said pistoning air to and away from said pistoning chamber, said valve being located above the level of said water outlet and said cover being located substantially below said water outlet but above said: perforated plate so that it lies near thesurface of the bodyof water immediately after the cessation of pistoning.

BER-TEAM NORTON. 

